treach·e·rous/`trɛtʃərəs; ˈtretʃərəs/ adj 1 extremely dangerous because you cannot see the dangers 暗藏危险的，凶险莫测的: Black ice on the roads is making driving treacherous. 路面上的黑冰威胁着行车安全。 2 someone who is treacherous cannot be trusted because they secretly intend to harm you 不忠的，背叛的，阴险的: his treacherous colleagues 他那些阴险的同事